Context: When the game first came out GW used to be very very challenging to the point that only it felt like a real milestone if you finished all of it, to the point that this board seemed to be filled with messages that it was too hard. It was re-balanced several times and is now sim-able.
Issue: I would like a better testing ground for some of my teams and GW seems like the best place to do it but it is so easy. For those with a more mature inventory it would be great if GW was more of a challenge, partly to test different teams out, and partly for fun and the challenge.
Solution: Keep the difficultly exactly the way it is, unless if GW is now sim-able by the player. At that point, bump up the difficulty. It allows people who want to try something harder an opportunity to do so, but at the same time for those that do not want to bother with it, they can just sim as they probably are doing so today. To me it looks like a win-win.